Adobe Sign changes date default value format when uploading a filled form

We have an form that includes having people enter a date for the beginning of a two week time period and then autofills the rest of the two weeks.  No problem.  Some people enter only the Month and day and it formats nicely in the form.

When we use that filled out form to get the signatures in Sign, we get an error messge. The date reverts back to what they typed in (mm/dd) for the default value instead of the formatted date (mm/dd/yy) which shows up on the form. (See attached)

Am I doing something wrong? Can I get Sign to use only the formatted value rather than the default value the person enters?

Or do I have to change it every time?  Thanks.